Owing to certain intrinsic advantages of conventional or cable-operated assistive appliances, many upper- extremity amputees prefer using simple voluntary opening (VO) split hook terminal devices for some tasks. Amputees who regularly contribute their time and expertise helping ADA develop innovative new assistive appliances continue to request the company create for all upper-extremity amputees a refreshing new split hook unit. In particular, three functional innovations are highly desired: 1) a means to readily adjust pinch force; 2) a robust new flex-hinge that is impervious to dirt and debris and that will not jam; and 3) stronger, more functional, and more visually appealing grasping contours. These amputees have further requested that new engineering materials and manufacturing processes be exploited to realize a unit having minimized weight, superior structural strength, and significantly lower manufacturing cost. Beyond this domestic market, the device once developed holds the potential to significantly improve the lives of disadvantaged amputees in developing countries who survive primarily by subsistence farming. Minor adaptations to the underlying technology will maximize its utility for agrarian purposes to enhance these amputees' farming productivity. The Primary Objective of this SBIR program is to create a versatile next-generation VO split hook terminal device that delights upper-extremity amputees in the United States and abroad, and that can be manufactured for low cost to facilitate global distribution. In Phase I, ADA will develop a viable design for its split hook concept implementing the three innovations mentioned previously, and that exploits new materials and manufacturing processes to minimize manufacturing cost. ADA's proven virtual engineering process will yield a viable design, which will then be empirically validated using rapid prototype models. Amputees and professional clinicians will critically examine these models and provide additional feedback and guidance. Following updates to the basic design, robust functional prototypes will be fabricated and evaluated by fifteen (15) human subjects in extensive field validation trials conducted in accordance with an Institutional Review Board (IRB) approved protocol. Phase II comprises conducting additional and unusually demanding trials, establishing manufacturing infrastructure, and adapting the technology for distribution in developing countries by existing O&P clinical outreach humanitarian agencies. Phase III encompasses distributing the new appliance both domestically and overseas to benefit amputees. PUBLIC HEALTH RELEVANCE. ADA aims to create a versatile next-generation split hook terminal device using advanced materials and manufacturing processes that incorporates three functional innovations long sought by amputees who prefer conventional devices for certain tasks. This new split hook satisfies a clear domestic need while offering an attractive low-cost option for disadvantaged amputees in developing countries who need an assistive appliance that enhances their productivity to improve quality of life. [unreadable] [unreadable]